Archive/ Counter-Archive is a two-day conference with associated exhibition and web project offering fresh thinking and dialogues on the current relations between contemporary art and the archive. The focus of the conference has been shaped by the ways artists are responding to the archive, but also by the histories - and future possibilities - of practices of collecting and drawing.

User photographs can still be found on many social networking sites even after people have deleted them, Cambridge University researchers have said.

They put photos on 16 popular websites - noting the web addresses where the images were stored - and deleted them.

The team said it was able to find them on seven sites - including Facebook - using the direct addresses, even after the photos appeared to have gone.

Facebook says deleted photos are removed from its servers "immediately".

The Cambridge University researchers said special photo-sharing sites, such as Flickr and Google's Picasa, did better and Microsoft's Windows Live Spaces removed the photos instantly.

To perform their experiment, the researchers uploaded photos to each of the sites, then deleted them, but kept a note of direct URLs to the photos from the sites' content delivery networks.

When they checked 30 days later, these links continued to work for seven of the sites even though a typical user might think the photos had been removed.

Lazy approach

Joseph Bonneau, one of the PhD students who carried out the study, said: "This demonstrates how social networking sites often take a lazy approach to user privacy, doing what's simpler rather than what is correct.

US scientists say they have successfully reversed the effects of Alzheimer's with experimental drugs.

The drugs target and boost the function of a newly pinpointed gene involved in the brain's memory formation.

In mice, the treatment helped restore long-term memory and improve learning for new tasks, Nature reports.

The same drugs - HDAC inhibitors - are currently being tested to treat Huntington's disease and are on the market to treat some cancers.

They reshape the DNA scaffolding that supports and controls the expression of genes in the brain.

“ We need to do more research to investigate whether developing treatments that control this gene could benefit people with Alzheimer's ”
Rebecca Wood of the Alzheimer's Research Trust
The Alzheimer's gene the drugs act upon, histone deacetylase 2 (HDAC2), regulates the expression of a plethora of genes implicated in plasticity - the brain's ability to change in response to experience - and memory formation.

Ministers are to trim up to 850,000 DNA profiles from the current total of 4.5m on a national database after a court ruled innocent people must be removed.

Those arrested, but later released or acquitted, will have their profiles wiped after between six and 12 years.

Officials warned the changes could reduce the number of crimes solved.

But opposition parties accused the government of "giving as little as possible" in response to the European Court of Human Rights judgement.

Last year the court ruled that the database in England and Wales' was illegal - unlike Scotland's which was deemed "fair and proportionate".

“ Why does [the DNA profile] need to be held on file? That shouldn't be the case unless you've been convicted ”
Dr Helen Wallace, Genewatch
The court said rules allowing police to keep everyone's profile on store were blanket and indiscriminate because they did not differentiate between criminals, the severity of their crimes and innocent people who had never been convicted of an offence.

Current practices in England, Wales and Northern Ireland allow police to retain a numeric genetic profile of everyone arrested for a recordable offence - regardless of whether they are charged or convicted.

Google has launched two experimental products it hopes will change the way users search for pictures and news.

A feature known as Similar Images uses a picture rather than text to find other matching images.

Timeline presents information already available in Google News but organised and displayed chronologically.

Alongside these features is a new version of Google Labs, in which users can take a peek at what its thousands of engineers are working on.

Amid past criticism that Google has wasted too much time and effort on projects that have little impact, the aim of the Labs upgrade is to make prototypes available earlier.

"The idea we are trying to build here with Labs and the culture of innovation is to close the gap at the point of which a new idea is hatched and the time it takes to get into the hands of users for feedback," said Google director of product management R J Pittman.